


Between the Devil and the Deep Blue Sea

by PrettyQueerDear



Category: Gravity Falls
Genre: Alternative Universe - Pirates, Captain Cipher, Gay Pirates - Freeform, Gore, Human!Bill, M/M, Mutual Pining, Possessive Behavior, Pre-Relationship, Self cock-blocking, Siren!Dipper, Surprisely not from Bill, Violent Thoughts, possessive
Language: English
Status: Completed
Published: 2015-12-25
Updated: 2015-12-26
Packaged: 2018-05-08 13:38:48
Rating: Mature
Warnings: Graphic Depictions Of Violence
Chapters: 2
Words: 4,276
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5499035
Author URL: https://archiveofourown.org/users/PrettyQueerDear/pseuds/PrettyQueerDear
Summary: <blockquote class="userstuff">
              <p>Captain Cipher makes a deal with the devil of the sea in exchange for his life and now reflects on it.</p>
            </blockquote>





	1. Chapter 1

**Author's Note:**

  * For [Billdip Fandom](https://archiveofourown.org/gifts?recipient=Billdip+Fandom).



> The summary and title makes this story sound so intense and dramatic, but it's like not.
> 
> (Happy Holidays Billdip fandom)

He floated sluggishly against the warm water with his arms outstretched at his side and legs slightly parted. The soft waves washed the sand still clinging onto his body as he swayed with the currents. His blond locks swirling around his head much like golden halo. The white fabric of his shirt continuing to make the angelic image more true. From the distance he could hear his crew setting up camp on the beach with their constant holler and bustle. He sighed softly letting his eyes flutter closed and allowed the sound of the waves and wind relax him.

Abruptly a hand submerged him under water. He gasped in surprise, eyes shooting opening, as he felt the water engulfed him briefly before he was back to the surface just as quickly as he dragged under. He was back to floating on his back, this time laying against the larger body of another being. The same webbed hand that grabbed him slid down to his chest over his shoulders. A content sigh left soft lips next to his ear.

"Having fun there?" He coughed. Eyes and throat stinging from the salt water.

All he got in response was soft clicking noises and purrs as the siren's nose nuzzled his neck. The captain couldn't help the shiver that raked his spine as the other's nose and mouth slid across the sensitive skin. He closed his eye again allowing the roaming hands to caress his skin underneath his shirt.

"I don't get why you have to wear this here. Not like it keeps you warm or anything."

The captain smirked. "If you want to see me naked all you have to do is ask." He purred lazily.

He got a playful swat on his outer thigh for that comment. Dipper got along with the crew even singing along with them when they got too rowdy on deck and helping them fish when food supply was down, but he never got as playful with them like he did with Bill.

The creature continued it's movements in a flowing manner, fingers shyly skimming his waist band. The captain's breath hitched as a finger slipped beneath the fabric. The atmosphere became heavier around them. Bill frowned and rolled a bit to the right to submerged himself with the less suffocating water.

"Why'd you do that?" The siren asked when he resurfaced. Bill just blinked the water off his long eyelashes, dragging his hand over his face to wipe the remaining water off. The creature was clearly displeased with his actions. Dipper made grabby motions with his hands as he reached out for the small human. Captain Cipher swam just out of reach, a cocky smile on his face.

"Get back here." Dipper whined childishly. Bill ignored his request and instead swam towards shore.

Bill climbed the rocks that were clustered on shore to sit on. He pulled off his wet shirt that stuck to his body like a second skin and it made a hard splatting noise as the fabric hit the hot rocks. He turned back to see the siren looking intently at him. His fins were opening and closing like large fans in a peacock fashion.

"Guppy." Bill pulled himself up further onto land grunting when smaller rocks dug sharply  
into his feet. "Why are your fins doing that?"

Dipper's eyes dilated and his fins stopped. "Huh? D-doing what?"

The captain mimicked the motion with his hands watching as the siren turned a deeper shade of blue.

"I don't know what you're talking about." The siren smiled a little too innocently for Bill's taste before diving back into the water in a rushed manner. Bill narrowed his eyes, lips puckered in thought. It was now his turn to be displeased with the other's actions. He opened his mouth to call back the rascal.

"Captain foods ready!" A crew member hollered in the distance cutting off Bill's attempt to get Dipper's attention.

He whipped his head in the direction of the call. He debated about getting the fish to fess up now or getting some food in his aching stomach first. His stomach growled in protest and he begrudgingly agreed. Food now, discussion later. The pirate sighed as he began heading towards camp in a slow plot. As he walked down the sandy path, toes sinking into the minuscule pebbles, the man began to pondered a bit about what led him to his current position in life.

He made a deal with the bloody demon almost a year ago when it tried to drown him for a quick meal. They somehow reached an agreement where the sea devil promised not to consume his flesh or that of his crew so long as Bill provided food and knowledge of the human world. As a bonus the siren became part of his crew. Not many men could say they swam in the same waters as a siren and lived to tell the tale. Captain Cipher would even bet all his gold that no one else could say they had one as a crew member.

Not the first time his quick thinking and negation skills have saved the pirate's skin.

At first Bill doubted the creature's sincerity to their deal, waiting anxiously for the sea beast to strike them in their sleep. For weeks he would only see glimpses of the overgrown fish trailing his ship, his paranoia only getting worst when the siren didn't make a move. The creature had been playing a dangerous game seducing his crew from time to time. He'd flutter his eyelashes and twirled his chestnut curls around his webbed fingers. He even tricked some of them to give him gold and other world possessions. He'd leave a ghost of a kiss on their lip and a wink as his trademark. Bill was stuck between laughing or screaming in aggravation when the siren succeed in swindling his crew. Whenever he got complains from the crew he just tell them it was their own fault for falling for a pretty face.

Just when he felt like he was about to cut the deal Dipper finally made true of his promise as navy ship crossed path with them. The pirate captain and his crew prepared the cannons with weapons ready in clutched mitts, and spirits high for the coming battle. Then a velvet voice carried through the wind and mesmerized all who heard it. The sight that he and his crew witness was like that of a dream.

The soldiers dropped their guns and swords before going to mindlessly transfer the valuables from their ship to Captain Cipher's ship. At first there was confusion and fear in the air by the pirates until they spotted the siren sitting on the railings of the ship with his lips open wide, eyes closed, and singing. After the ship had been bared of all treasures the enemy lined up to be killed like helpless pigs.

One man survived a knife to the gut went unnoticed by the rest of the humans on deck. Dipper sluggishly dragged his body across the deck to the bleeding man with a sweet smile playing on his face. The man gave rasping pleads.

"P-please help me..."

"Oh you poor thing." Dipper cooed. "Let me put you out of you misery." His concerned voice becoming more husky as his hands rubbed the man's stomach before his claws impaled him. The man twitched and gave small moans of pain as the siren gutted him and pulled entrails out right in front of him. No one noticed the interaction between the two, much too entertained with all the bounty, until a cabin boy screamed in panic and hurled his food at the gruesome sight.

Dipper hardly payed him any mind and continued to eat the man alive right before the eyes of the rest crew that had gathered around to watch in morbid fascination, unable to peel their eyes away in disgust. Dipper just raised his blood stained claws to his mouth as a long pink tongue licked away the ruby fluid staining them. The creature couldn't hide the sadistic smile that took place on his gorgeous features, needle like teeth showing ripped skin stuck between them. The siren preened at the look of horror on everyone face, proud to strike fear into the hearts of his natural prey.

"Damn bloody fish, you're making a fuckin mess!" Bill cussed as shoved his way through the crowd, ignoring the way his hair stood on end when those blue orbs focused on him. The creature seem to debate his reaction before swallowing the rest of the flesh in his mouth. He had blood dripping down his wet jaw, water a turning a transparent pink as blood mixed in. It really was unsettling for such a beautiful face to be so horrifying at the same

"Sorry about that." He apologized not sounding sorry at all.

Grabbing the-now mercifully dead-man's body with one clawed hand and using his other, the siren dragged them back to the railing. A trail of blood streaking across the waxed wood was left in their wake. He easily dumped the remains of mangled body over board first and then turned to smirked at his captain as he waved good-bye before diving back in to the freezing waters below. The crew trusted him, but the siren and him knew the truth. Magic could out weight a bullet any day.

Bill shivered at the memory only being brought back to the present when his toe stubbed a hidden rock, cursing quietly at the pain it brought. Flexing his big toe to relieve some pain he went back to pondering about the unusual creature he had befriended over the course of the year.

Dipper wasn't the typical mermaid sailors wagged their tongues about at sea ports. He didn't have flowing long hair down to his waist and he lacked the perky breast and curvy waists the females of his spices. He was a obviously a sturdy male with a deep voice, yet any he wasn't any less breath taking than the females.

He had alluring blue eyes that matched the shimmering scales on his body. He was huge-something the siren took pride in-no longer the smallest guppy in the pod he once claimed to be. His powerful tail shimmered with deep blue scales, puffy white fins smooth as silk with black spots peppering them decoratively. He didn't have a single strand of hair apart from his hair on his head, skin smooth and clear with a light blue tint. Behind plump lips where needle like teeth that could shred off skin. His hands were webbed and retractable claws replaced finger nails... He was just as dangerous as the females.

That fact alone made Bill cautious when he held his end of the bargain. For months on end they would be at open sea and Bill refused to get into the water, the predator's natural habitat, so the only solution was using a fishing net which used a lever system to lift Dipper up to the railing of the ship. From there the captain would talk at and explain as much as he could about the human world to the siren. Dipper would ask several questions and questions on those questions until Bill got bored and refused to answer anymore for that day. They repeated this process for the following months..

The net eventually became some makeshift hammock for the siren to use freely and almost daily. Sometimes at night he would raised himself to the edge and they talk through the night. The captain had trouble sleeping and the siren only needed a few hours of sleep to survive. They'd talk about water routes, their childhoods and sometimes they'd just sit together in peaceful silence underneath the stars. Bill found himself looking forward to the night encounters.

The more time they spent together, the more they got to know about each other. Bill hadn't expect was for Dipper to be so human. He had expected some of the more animalistic characteristics that Dipper had displayed that day on the navy ship not some curious, intelligent, snarky, and defiant young man behind the pretty face that he knew today. It made his chest hurt a bit for unknown reasons.

Maybe that drinking was finally getting to him. Yeah probably that.


	2. Chapter 2

**Summary for the Chapter:**

> Dipper makes a deal with a desperate scheming devil as a way to get knowledge on the forbidden world outside the ocean.

He preferred to sing in a language humans didn't recognized even if he could sing actual words for his prey to understand. The song he was currently singing was in his native speech and it was doing a fantastic job of luring the bronze man to shore and into the water. Soon he found himself cupping the other's face with his tail was curling around his legs, loose enough for him to swim, but close enough to ensnare him when the time was right. Not like the man could out swim him in his environment, Dipper just felt too lazy to bother playing with his food today. He peppered a few kisses along the mans jaw, hearing the man let out a small gasp. He had stopped singing letting his prey become aware of his impending death. He pulled back to look at the man with a seductive smile playing on his lips.

Dipper had been watching the pirates from the water the last few days. They had taken a short break on this island where he liked to study the small ecosystem. He had quickly analyzed the situation and come to the right conclusion this human was the leader. Instincts were telling him to hunt, but when else would the opportunity to observe human social behaviors and habits come again? So he made the decision to wait patiently for three days and nights. He observed from the oceans depths, taking secret delight knowing that while they ignorantly swam in the same waters as him, he could easily enchant them all and have a feast. When he overheard some of the crew mention setting sail at sunset he decided it was time to strike.

"I like the sounds you make Captain Cipher." He teased before going back to nuzzling the man, a final kiss on his nose, scaly arms going to drape the pirate's shoulders. Bill's flesh was so warm and soft that Dipper couldn't hold back purring happily. This human was going to be a delicious meal for the following days.

Then the man did something odd; he started a conversation.

"I-I get the impression you've never spent much time around humans than?" The fearful under tones lingered in in his prey's words, but there was something in them that got Dipper's attention. Humans usually begged at this point, not ask questions about him. "I guess that means you don't know much about the human world than?"

Dipper blinked, stopping his hands soothing movements. "...No" he admitted. He had been forbidden to by his elders since he was a small guppy. His ears perked up with interest.

"Than how about I teach you everything I know? Things about culture, art, and music." The man tempted.

He was always been too curious for his good. This was obviously some desperate attempt for survival by the weaker being, still the temptation was too strong and the opportunity too great for him to refuse. When would he have another chance to learn about the mysterious and forbidden world around him?

"Keep talking." The words were leaving his mouth before his brain could process them properly. And so the man did.

Somehow by the time they reached an agreement the scheming devil managed to trick him into being part of his crew, but he supposed it was worth the amount of research he was going to get done thanks to unexpected encounter. Besides if he ever felt he was any danger or the man go back on his end of the deal he could just kill the tiny creature.

At first Dipper had tried to toy with him, tempt him, or unnerve him at least. He found the task harder than he first thought. The captain had learned to keep his guard up when he was around the siren so toying with him in any way was difficult. The last time he had done anything to the captain he got a rude hand gesture in return.

"If you wanna kiss anything, kiss my ass fish lips." That was the last time he tried blowing kisses the man's way.

He hadn't flinched in at seeing him devour others of his spices, slightly disgusted and disturbed maybe, but not frighten or horrified like his crew. From what Dipper could tell the man had few morals and cared little for others outside his crew. Not that he showed his frustration, the last thing he needed was for the human to know that. Still the man give him anxiety from time to time with his erratic actions.

He found the crew was much more responsive to his advancements than the captain. He used that to his advantage and managed to get some human currency to examine. Any worldly possessions he took were studied and taken apart by him in an effort to try and figure out what they did and their purpose. If he ever got stuck on something he reluctantly asked the pirate captain to tell him. Plus he found it amusing when the pirate glared at him for flaunting the swindled objects of his crew.

The more time he spent with the human the more he found himself reluctantly content in his presence. He learned the man had a bit of reputation for being slightly if not completely insane and having a knack for mind games. Everyone on board he asked either respected, or feared (good portion both) their captain. He didn't think the captain to be so clever, much more intelligent than he expected some outlaw to be. (Although their deal would have been a waste of time for Dipper if the man couldn't teach him basic spelling he supposed.) Dipper had come to find the mind games they played addicting and he may have found himself enjoying the banter-flirting-between them. The human was interesting, something dangerous, and he was fascinated with him.

The human seemed to have grown fond of him as time passed and Dipper found himself considering him a friend. At night they spend talking to each other about themselves. Dipper had learned what different lives they truly lived. A bond of trust and acceptance formed over the months between the two much to the surprise to those on board.

Dipper had confided in Bill that at times he still felt the instinct at the back of his head to drag him down into the water and drown him. He even went on in detail of the thrill he got when he watched the life leave the panicked struck eyes of his prey, and watched them take one last departed breath. At first Bill had avoided going into the water with Dipper, but he soon reasoned that if he really wanted to drown him nothing could prevent him from doing so.

Right now his captain was floating leisurely with the soft rocking waves, without a care in the world, in the same water with the predator that tried to kill him months ago. He didn't know wether to be pleasantly delighted at the trust Bill showed with him or insulted that his prey no longer feared him. He settled somewhere in between. It was time to teach the captain a lesson. He swam in the man's direction, resurfacing a few times to see if the man still remained unaware of the oncoming danger.

A few members of the crew spotted him, he put his finger to his lips when he looked at them, a silent signal humans used, to not blow his cover. It took some time, and effort until he gained the trust of the crew after his fun with them, but he did. Some nodded in enthusiastic agreement, some shook their heads in exasperation, and a few looked on with concern. (The latter were the few who hadn't warmed up to him from his show on the navy ship the first time.) Each time he checked the man looked at peace in the water and took a moment to appreciate the view.

Unlike the light azure hue on his skin, Bill's skin was a dark caramel like the bark of trees on land. The oddest thing he knew about humans was that they had hair everywhere unlike sirens who only grew some on their heads. Bill's hair was longer than most males, but shorter than that of females, the wavy locks reaching just above his shoulders. He kept the golden locks messily tied with a black silk tie. (Dipper liked to untie it from time to time.) Most the males on board let their facial hair grow, Bill on the other hand liked to kept his short, shaving every few days. Dipper loved the feeling of the man's whiskers on his skin, loved mushing their cheeks against each other and rubbing his face against the scratchy skin.

He dived under the captain's spread out body, before abruptly disturbing the soothing tides as Bill struggled against his actions on instinct. Just as suddenly as he submerged the man they were back to the surface once more. Bill's small body place on top of his own as the captain was left sputtering out water from his mouth. The sight was amusing to him.

"Having fun there?"

He didn't feel the need to answer with words knowing the man already knew the answer to his own question. He let his hands roam the warm body laying flush against his freely. He didn't like the annoying fabric he was wearing though.

He wondered out loud why he bothered wearing such things in the water and got a lewd answer out of all things! He lightly swatted the man for that embarrassing remark, his gills fluttering in excitement at the thought. Hands were already back to exploring the other's body, he sighed in content at the feeling of the soft flesh at his finger tips, going lower down in sweet caresses. He would have kept going about this pleasurable business if his human hadn't decided to take a dive that moment.

The cocky human refused to answer his question on his actions and instead went back to rocks by the shore. Dipper shallowed the disappointment in his chest and followed the human. By the time he reached shore the man was at last removing that useless white rag. His body was average for his spices, not too skinny or fat, but slightly lean. The bronze body was covered with strange markings in black ink. The most noticeable being the one on his chest which consisted of a wheel with a one eye triangle.

Much to his embarrassment he was caught staring and the human as observant as ever asked him on his fins. He tired to act casual, pretending to not know what he was taking about. From Bill's facial expression it didn't work, so he panicked and made a quick retreat. Isn't that funny, the siren swimming away from the human?

Heaven must have been smiling upon him because the captain was quickly distracted with promises of food. He swam leisurely, close enough to the shore to spy on the captain making his way to camp, yet far enough to avoid being spotted with his head above the water. A part of him longed to trade his tail for a pair of legs to be able to join his affections.

Over the following weeks he had resorted to less than proper measures to grab the man's attention. Showing off his fins was similar to how male peacocks attracted mates, but to sirens this behavior held a more scandalous meaning. Flashing one's fins the way he was doing was considered lewd. Bill was unaffected not surprisedly, it wasn't like he knew what Dipper was doing.

Still his trying and frankly the failing of seducing the pirate captain was little disheartening if he were honest with himself. He debated wether it was time he quit the silly game and go back to his home and possibly visit his pod. He got enough information and stories to share with Mabel and the rest of his pod. It'd be so easy just to swim back and cut their deal with no one harmed. And never see Bill again...which was probably for the best.

But his blood boiled at the thought of some nameless lover stealing away his beloved captain away from him. He'd imagine singing to them and leading them off the edges of cliffs to watch their fragile bodies plummet. Or their death being dragged out as he would slam their face into the cold unforgiving water and pulled them for a brief moment of air before slamming them back under, repeating the tortuous cycle until they stopped their helped flailing. Or even eating them alive as they begged for mercy. The result would alway be the same; Bill loving him, being with him and only him. A feeling of sick satisfaction filled his being as he imagined his fantasies play out.

He was brought out his musing when his captain stumbled over something on shore. He chuckled at the man's small misfortune. At much as he wanted his captain all to himself he didn't think he was ready for him to find out about his true feelings. He figured he waited this long he might as well stick around.

**Notes for the Chapter:**

> I honestly never took this story as dark until I retread it. I guess the title fits it now.

**Author's Note:**

> Wow Bill so gay and he doesn't even know it.
> 
> Comments, questions, and feedback welcomed here or at http://prettyqueerdear.tumblr.com!
> 
> (Feel free to correct me on any errors in the story)


End file.
